The heroes in Dota 2 are defined by the roles that they are suited to play as a combination of their attributes, abilities, and items, and the ways that these shape the game. Although the abilities of heroes may suit a variety of purposes and can be used in a variety of ways in different situations, roles nonetheless exist to define the playstyle a hero is expected to conform to, as well as the actions they are meant to perform within a game. As strategic combat between two teams of five heroes with distinctly different abilities and strengths is the central conflict of Dota 2; players need to be well informed of their role within each team, as well as the roles of the enemy heroes. Even more importantly, players should keep in mind how their ability build and item build affects their heroes and fares against the ability and item builds of enemy heroes in the context of every single game so that they make sound decisions on the abilities and items that they choose to get.
Carry
Will become more useful later in the game if they gain a significant gold advantage. Also known as a Hard Carry, a Carry is the hero that a team rallies around late game. (The role’s name is derived from the act of “carrying” a team; that is, to bear the responsibility for ultimate victory.) They are the ones expected to have the highest number of hero kills for their teams. Carries typically lack early game power, but they have strong scaling skills; thus, they are highly dependent on items in order to be successful. In addition, Carries often have a built-in escape mechanism. Usually, carries rely on strong and fast physical attacks, but this is not always the case. Having more than one Carry will cause competition within your team for resources, which typically results in a number of underpowered Carries. For this reason it is highly recommended that a team have only one Hard Carry, because as the game progresses a hard carry must begin to secure the majority of the kills. Any Semi-Carries (heroes usually Gankers/Nukers that have attained sufficient level and gold advantage to avoid diminishing in the late game) must be prepared to forfeit kills to the Hard Carry after the early game. Carries typically are relegated to a side lane early on with one or more Lane Support heroes to babysit them until they collect the necessary items to farm independently.
Nuker / Ganker
Can quickly kill enemy heroes using high damage spells with low cooldowns. Also known as a Ganker, these are heroes with abilities that deliver high damage early in the game. Their goal is to give the team an early game advantage during the laning phase by killing enemy heroes in their proper lanes. Many Gankers can become a Semi-Carry if they are successful in their efforts, but because their abilities do not scale they will usually suffer in late game unlike a true Carry.
Initiator
Good at starting a teamfight. Initiators are heroes who can safely and advantageously start a team fight. These heroes typically have strong area of effect damage, disable, or similar skill to affect the positioning of the enemy team. Although it is common for an Initiator to be a Durable hero, this is not always the case. Usually there is an attempt to quickly eliminate an enemy Carry, which will lure the enemy team – thus initiating a large scale battle.
Disabler
Has a guaranteed disable for one or more of their spells. Disablers are heroes with abilities more focused to reliable crowd control, either by single target or by area of effect. They can act as Semi-Initiators in ganks when the number of enemy heroes to be killed is few in number – a true Initiator’s cooldowns are best saved for large confrontations.
Durable
Has the ability to last longer in teamfights. Also referred to as a Tank, these heroes have the potential to sustain a large amount of incoming damage from the enemy. They tend to have large amount of HP, HP regeneration, armor, or magic resistance. They often have abilities to mitigate damage, avoid damage completely, or weaken the power of enemies. Strength heroes are well known to fulfill this role because their primary attribute Strength grants HP.
Escape
Has the ability to quickly avoid death. Escape heroes are heroes equipped with one or more escape mechanisms which allow them (or sometimes their allies) to avoid damage and abilities while retreating or repositioning themselves during a teamfight or gank. Escape heroes are particularly suited to soloing the “suicide lane” or short lane, as they can turn situations where death is inevitable into a temporary delay in farm. Escape mechanisms include movement speed buffs, Invisibility, Teleportation, and Evasion.
Support
Can focus less on massing gold and items, and more on using their abilities to gain an advantage for the team. Supports are heroes whose purpose is to keep their allies alive and give them opportunities to earn more gold and experience. Supports will usually come with skills such as healing spells or disables; and generally have low damage output but a powerful-yet-situational nuke. Like Semi-Carries, Supports are not dependent on items (with some exceptions). Most of their gold will be spent on items for the benefit of the team such as Animal Courier, Observer Wards, Sentry Wards, and Smoke of Deceit. Supports are typically paired with the team’s Carry at the start of a game. This is because the Carry tends to be the weakest and most gold-hungry member of the team early on. A Support should always try to forfeit kills to the team’s Carry, only performing the kill if none of his allies are able to do it. Supports are heroes who “babysit” and help their team’s Carry control the lane in the early stages of the game. They are able to either repel enemies from your team’s carry or to allow the carry to continually stay in the lane using abilities that replenish either health or mana. Common traits of Lane Supports are long-ranged right-click attacks and abilities that are highly useful from level 1 and up. They should always lane with the team’s Hard Carry, as aside from supporting them; their lack of dependence on gold and levels means the Carry can take all the farm for themselves without running the risk of soloing a lane.
Pusher
Can quickly siege and destroy towers and barracks at all points in the game. Pushers are heroes who focus on bringing down towers quickly, thereby acquiring map control. If they succeed, they often shut down the enemy Carry by forcing them away from farming. They typically have skills that fortify allied creep waves, summon minions, or deal massive amounts of damage to enemy towers.
Jungler
Can farm effectively from neutral creeps inside the jungle early in the game. Junglers are heroes that can jungle neutrals at the start of the game, rather than lane. This allows for there to be two solo lanes, which in turn allows two allies to benefit from solo farm instead of one. Junglers typically have skills that allow them to convert neutral creeps, summon minions, or sustain themselves through damage; and the ability to Jungle is found in Heroes of all classes. Although having two solo lanes and a Jungler produces a significant gold and experience advantage, it increases exposure to enemy ganks. To alleviate this, make sure your second solo hero is a Semi-Carry in the long lane (bottom for Radiant and top for Dire). This way, the creeps fight closer to the tower and the Jungler can quickly come to his aid or gank; there is a reason why this lane is called the “safe lane” and the other side lane the “suicide lane”.